418 INTERNAL SECRETIONS OF PANCREAS AND SPLEEN. 



the digestion of albumins in the duodenum to cease, as shown 

 in the Schiff-Herzen experiments. That the conversion of 

 food-starches into maltose is also, owing to the absence of 

 amylopsin, arrested, is evident. The only substitute for this 

 ferment available is ptyalin; but though the salivary secretion 

 at least, its ptyalin is quantitatively increased after removal 

 of the pancreas, it is inadequate to convert all the starch 

 required to compensate for the glycogen used. The glycogen, 

 gradually converted by what ptyalin is swallowed with the 

 saliva between meals, therefore disappears. The fact that 

 ptyalin converts starch partly into dextrose greatly hastens 

 the disappearance of the glycogen, the primary sugar of which 

 is mainly maltose. It would seem, therefore, that the glycosuria 

 following extirpation of the pancreas is due to the action of ptyalin 

 upon food-starches. 



That the salivary secretion is gradually increased after 

 removal of the pancreas is sustained by experimental evidence. 

 Aldehoff 35 observed that glycosuria only appeared from 24 to 

 48 hours after the operation in turtles; in frogs it only ap- 

 peared after four or five days, "slight at first, becoming more 

 intense later on." Minkowski 36 found that it sets in after two 

 or three days in dogs, under the same conditions. Again, dur- 

 ing its passage through the stomach ptyalin acquires increased 

 energy as a ferment. Charles 37 refers to this question as fol- 

 lows: "Chittenden and Griswold find that the presence of acid, 

 as hydrochloric acid, to the amount of 0.005 per cent, decidedly 

 increases the diastatic action, while an increase beyond this 

 diminishes it, the action stopping with solutions of acid from 

 0.1 to 0.4 per cent.; the diastatic action of the saliva would, 

 therefore, appear soon to cease in the stomach, but the peptones 

 in that organ exercise a decided influence on salivary digestion, 

 stimulating the ferment to increased action, particularly in 

 presence of acid, which by itself may completely prevent the 

 conversion of starch into sugar." Mering found that starch 

 acted on by saliva yielded dextrin and maltose at first, then 

 after some time grape-sugar. 



M Aldehoff: Zeitschrift fur Biologie, Munich, Bd. xxviii, p. 293, 1892. 

 w> Minkowski: Loc. tit. 

 7 Charles: Loc. tit. 



